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Feb. 1, 2010 -- Twelve weeks of fish oil pills made teens at high risk of
psychosis much less likely to become psychotic for at least one year.

The finding comes from a placebo-controlled clinical trial that enrolled 81
young people -- average age 16 -- teetering on the brink of psychosis.

A year after entering the study, 11 of the 40 teens treated only with
placebo pills developed a psychotic disorder. This happened to only two of 41
teens who began the year with 12 weeks of fish oil capsules rich in omega-3
fatty acids.

No other intervention, including psychiatric drugs, has achieved as much for
so long after treatment stopped. Moreover, antipsychotic drugs tend to have
serious side effects, including weight gain and sexual dysfunction. Fish oil
pills have no serious side effects.

The study suggests that to prevent one case of psychosis, four high-risk
young people must be treated. That's the same level of efficacy seen with
antipsychotic medications, note study researcher G. Paul Amminger, MD, of the
University of Vienna, Austria, and colleagues.

"The finding that treatment with a natural substance may prevent or at least
delay the onset of psychotic disorder gives hope that there may be alternatives
to antipsychotics for the prodromal phase [symptoms leading up to psychosis
onset]," Amminger and colleagues suggest.

Earlier studies have suggested that omega-3 fatty acids can alleviate
clinical depression and other psychiatric disorders, although there have been
mixed results.

It's not clear whether the fish oil pills help people with established
psychosis. Despite having worrisome symptoms, none of the teens in the Amminger
study had ever had a full-blown psychosis.

It's also not clear how fish oil might prevent psychiatric disorders.

Amminger and colleagues note that people with schizophrenia tend to have low
levels of omega-3 fatty acids, suggesting that the mental illness could be
linked to a defect in the ability to process fatty acids. There's also evidence
that fatty acids interact with chemical signaling in the brain.

Particularly relevant to the Amminger findings is the suggestion that
omega-3 fatty acids protect brain cells from oxidative stress.

Amminger and colleagues warn against over-interpretation of their findings.
It may be that fish oil works better in young people with pre-psychotic
conditions than in older people with more established psychiatric disorders.
They do, however, strongly urge further research.

The study appears in the February issue of Archives of General
Psychiatry.